FIELD: mechanics.
SUBSTANCE: invention relates to pipe joints. Expandable pipe joint incorporating tubular internal member (EM) and furnished with internal thread (FM) comprises the first annular edge (L1) with the first axial bearing surface (SB1), first inner surface (SI1), first outer surface (SE1) and second bearing surface (SB2). It also comprises external tubular element (EF) furnished with external thread (FF), second annular edge (L2) provided with the third bearing surface (SB3), second outer surface (SE2), second inner surface (SI2), third inner surface (SI3) and fourth axial bearing surface (SB4) making, along with the second outer surface (SE2), annular support (LO) corresponding to the aforesaid first edge (L1). Internal tubular element (EM), in its initial position, contains a local annular bulge (SA1) at the level of the fourth inner surface (SI4) terminating in the second bearing surface (SB2). External tubular element (EF) accommodates, on its third inner surface (SI3), annular groove (G1) arranged, after screwing out, at the level of the first inner surface (SE1) and annular bulge (SA1). Internal and external tubular elements are arranged so that to allow, after screwing out, housing first edge (L1) in annular support (LO) and the first and third support surfaces thrusting against each other so as to ensure, in plastic strain conditions, forming annular ledge (EP) in diametric expansion, the aforesaid ledge being formed at the level of the first outer (SE1), representing at least, partially, the structure of annular groove (G1) and being in hermetic and compressing contact with the said groove.
EFFECT: pipe joint higher reliability.
36 cl, 12 dwg
